I have a new project where the customer desires the 8052 clone to implement two analogue outputs. I am researching various chips and looking for those with 12-bit D/A converters on board.

Has anybody worked on, designed, or seen a circuit that can easily implement a 4->20 milliampere output AND a 0-10V output. I would be interested in one of two configurations.....

1) A circuit that has a single set of output pins that can he configured via a port pin to produce either a 0->10V or a 4->20mA output.

2) A circuit that has two outputs that simultaneously produce the 4->20mA output and the 0-10V output in proportion to each other to high accuracy.

Michael Karas